Chlorine Resistance in Salmonella Typhimurium and Campylobacter jejuni Isolated from Poultry Processing Line

Salmonella Typhimurium and Campylobcater jejuni are major food-borne pathogens that continue to persist in the poultry processing industry and cause health and economic burdens. Chlorine is commonly used to mitigate bacterial contamination in poultry processing. However, inducing of adaptive stress response mechanism in sub-lethal exposure limits the effectiveness of chlorine. In the present study, we determined the effect of pre-exposure to chlorine on chlorine tolerance in S. Typhimurium and C. jejuni. MIC and MBC were determined in caecal, neck skin, post– chill carcass washing, and the environmental isolates. The carcass washings were exposed to either 3-5 ppm, 20-30 ppm, or 40- 50 ppm of chlorine in the chill tank and MICs and MBCs were significantly higher (p<0.05). Notably, 60% of C. jejuni isolated from the carcasses in a 20-30 ppm chill tank showed the highest MBC of 160 ppm. Chlorine-resistant percentage in S. Typhimurium and C. jejuni of the carcass was 78.8% and 83% respectively, while 94.1% and 80% of resistance were detected in 20-30 ppm chill tank isolates. The highest resuscitation detected carcass washing isolates exhibited the sub-lethal injury. Chlorine resistance limits the space to work with concentration adjustments. Therefore moving to alternative chemical and novel multi-huddle interventions is crucial.